As disclosed in this prior specification it has long been appreciated that paper-based transactions such as checks or gift vouchers for redemption are both costly to administer and prone to forgery. In addition as businesses world-wide increasingly out-source non-core activities to specialist third parties, it is apparent that there is a need for a flexible and secure money transfer system for handling even relatively small sums of money so as to accommodate retail transactions which at the lower level can correspond to single inexpensive items in a retail store. However, the processor system disclosed in the above GB Patent Specification, whilst extremely flexible in some aspects is essentially concerned with handling individual transactions. Thus the present invention is concerned with providing improvements to the basic processor system disclosed in GB Patent Specification No. 2364816 so as to provide added functionality, thus substantially widening the applicability of the system in a number of aspects.